Spark plug



June 22 1926.

H. GROSSER ET AL SPARK PLUG Filed Jan. 29, 1925 Fig.4.

Fig. 3.

Patented June 22,1926. v UNITED STATES 1,590,022 PATENT OFFICE.

EEBMANN GBOSSEB-AND FRANZ 6308813, 01 DENBTEDT, Gim- SPABK PLUG.

Application filed January 28, 1925, Serial No. 5,590, and in Germany November 8, 1884.

, time, as the threads stick and the iron parts being hot the hands of the operator are easily burnt. The removing of the cartridge reuires more or less time in accordance with t e number of threads.

According to the invention only one mani ulation is required for removing'the c'artridge as the cartridge is locked on the holder by a cap fixed on the holder by a bayonet joint. The cap has at the lower edge 'an in- 1 trated by wardly directed horizontal flange cut away at two opposite points and the holder has at its upper edge an outwardly directed flange cut away at two opposite points. In the cap a square wire spring is inserted. The two opposite corners of this wire spring which are situated over the flanges of the cap are bent upward and the two other corners are bent downward so that they are lpressed upon the two opposite portions of ,t e flange of the holder when the bayonet joint is closed, the spring being thus put under tension and the cap securely held 1n the closed position. When the ca is rotated to disengage the extensionsof t e cap from under'the flaps 0f the holder the upwardly directed corners of the spring will exert'a pressure upon the cap in upward direction so that the removin of the. cap is facilitated.

is mode of fixation presents further the advantage that the spark plug cartridge can have a cylindrical sha e whereby the manufacturing of the cartridge and of the spark plug is sim lified and rendered cheaper.

An embodiment of the invention is illusway of example on the accompanying drawing, in which: I

ig. 1 is a 1011 'tudinal section.

Fi 2 is a si e elevation, the cap lifted ofi t e cartridge being shown in'section.

Fig. 3 is a plan view of the cartridge without cap.

Fig. 4 shows the cap seen from below.

The cartrid a of the spark lug b'is cylindrical and mounted in a holder 0. A cap f having an an lar securely fix the cartridge a in the holder 0. With this object in view the holder has a lower e ge of said cap said flange head 9 serves to 7 two opposite inwardly directe extensions e are formed. The cap is fixedrin the holder by means of the bayonet joint formed by the extensions d and e.

In the ca 6 a square wire spring 71. is located which as two opposite corners bent in upward direction the two other corners i of the spring being bent down so that they project into t e gaps between the extensions e. When the cap f is placed on the holder the downwardly turned corners i of the sprin h bear upon the outwardly directe extensions (1 of the holder so that when the cap is pressed down and rotated to close the bayonet joint the spring h is put under tension and the cap is strongly pressed upon the holder. When the capis rotated in opposite direction to open the bayonet joint the cap is. lifted by the pressure of the spring h as soon as the extensions 0 of the cap register with the ga s between the extension d of the holder, t e removal of the cap being thus facilitated.

W'e claim An improved spark plug holder comprising in combination a cylindrical holder for the spark plug, an outwardly directed horizonta fiangeat the upper edge of said holder said flange being cut away at two opposite oints so that two horizontal extensions are ormed, a cap having a perforated head through which said spark plug projects, an inwardl directed horizontal flang?e at the ing cut away at two opposite points so that two horizontal extensions are formed which together with the extension of the holder forma bayonet joint, and a square wire spring inserted in said cap said wire spring having two opposite corners bent up and two other corners bent down said bent down corners projecting into the gaps between said horizontal extensions at the lower edges of said cap substantially as described and shown and for the purpose set forth.

In testimony whereof we aflix our signatures.

' jHERMANN GROSSER. rmzenossna. 

